From quality inspection to quality assurance

Summary Systematic quality assurance, e.g. in accordance with the provisions of ISO 9000, requires not only the targeted use of quality as a management tool, but also a revised attitude to operational procedures. Although sophisticated checking of the final results of a procedure (e.g. results of analyses, sales products, reports) meets the legal requirements and often also the customers' requirements, this misses the chance of being able to influence the quality of a final result at the earliest possible stage. It is then only possible subsequently to take the uneconomic decision as to whether the result of the work is useable or must be discarded or the object reworked. Within quality assurance, all operations are to be considered as processes with the aim of arriving at a statistically controlled process. The advantages of statistical process control are explained by way of examples from analytical procedures and production. The status of internal audits is explained as it interrelates with process control.     

Assignment of the 5,6-Double-Bond Configuration in Iloprost and Isoiloprost from 13C-NMR Shifts Determined by 2D Methods

The configurations of the 5,6-double bond in the carbacyclins iloprost ( 3 ; (E)) and isoiloprost ( 4 ; (Z)) are based on a complete assignment of the ¹³C and ¹H resonances determined by 1D and 2D ¹³C-NMR and ¹H-NMR methods.     

Semiquantitative analyses by secondary ion mass spectrometry using one fitting parameter

Summary A procedure for SIMS semiquantitative analysis, based on the use of one fitting-parameter, has been applied to metal and mineral standards with satisfactory results. Values of this parameter for various matrices are given, and prospects for analyses involving no reference elements are discussed. Analytical accuracies obtainable for individual elements are assessed in terms of matrix-independent error factors.

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Zusammenfassung Eine Methode zur semiquantitativen SIMS-Analyse, die im Gegensatz zu den aus der Literatur bekannten Verfahren nur einen Anpassungsparameter benötigt, wurde mit gutem Erfolg an Metall- und Mineralstandards getestet. Werte des Anpassungsparameters für verschiedene Matrices wurden angegeben und Aussichten für eine Weiterentwicklung dieser Methode in Richtung auf standardfreie Analysen wurden besprochen. Die analytische Richtigkeit für einige Elemente wurde mit Hilfe von matrixunabhängigen Fehlerfaktoren abgeschätzt.

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Presented at the International Symposium on Microchemical Techniques 1977, Davos, May 1977.     

Serum Chloride Optical Sensors Based on Dynamic Quenching of the Fluorescence of Photo-Immobilized Lucigenin

This article describes the preparation and performance of an optical sensor for continuous measurement of chloride at extracellular (serum) levels (20–200mM). The sensor is based on dynamic quenching of the fluorescence of lucigenin which was photo-immobilized on a hydrogel. Quenching occurs via a collisional mechanism, and the decrease in fluorescence intensity on exposure to 100mM chloride typically is –60%. It allows the determination of chloride in the 1 to 200mM concentration range, with a precision of ±3mM at 120mM. Bromide, iodide and salicylate act as interferents, while the effect of pH and oxygen is negligibly small. The sensor displays strong fluorescence intensity, excellent reproducibility, long-term stability, response times in the order of 2–5min, and is used in a commercial serum and blood chloride analyzer.Received January 21, 2003; accepted April 6, 2003 Published online July 28, 2003